Thermally Self-Stabilizing LED Module

ABSTRACT

An improved LED module that is thermally self-stabilizing, and that is able to be retrofitted into an existing flashlight is provided. In one embodiment, the LED module includes a light emitting diode, an amplifying circuit and a microchip. The amplifying circuit includes a temperature sensing device to sense heat from the light emitting diode. The output of the amplifying circuit is input to the microchip which output to a switching device that regulates energy that is delivered to the light emitting diode. The switching device may be part of a boosting circuit, a bucking circuit or an inverting circuit.

CROSS REFERENCE TO RELATED APPLICATION

The application filed herewith is a continuation application of U.S.patent application Ser. No. 11/227,768, filed on Sep. 15, 2005, entitledImproved LED Module.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The field of the present invention relates to a lighting moduleincluding a light emitting diode (LED), and pertains particularly to anenergy regulating, thermally stable LED based module for use in handheld portable lighting devices, such as flashlights.

2. Background

LEDs have been used in various applications including illuminatingwatches, transmitting information from remote controls, and formingimages on jumbo television screens. More recently, LEDs have been usedin portable lighting devices (such as flashlights), because, among otherthings, LEDs can last longer, produce light more efficiently, and can bemore durable than incandescent lamps commonly used in conventionalflashlights. Moreover, because flashlights that use incandescent lampsdominate the field, LED modules (a module that uses an LED as its lightsource) have been designed that can be retrofitted into existingflashlights.

A problem with simply replacing an incandescent lamp of an existingflashlight with an LED module, without more, is that it fails to operatethe LED at its potential lighting capacity under a thermally stablecondition.

It is known that LEDs produce more light with increased forward current.In situations where available voltage is abundant, the LED may be drivenclose to its maximum forward current value to produce more light.However, where the available voltage is limited or depletes over time,such as in the case of a battery powered flashlight, delivering aforward current close to the LED's maximum value may not be possible. Asimilar concern exists if the battery or batteries contained in anexisting flashlight provides too much voltage, thereby delivering aforward current above the LED's maximum value, which will result indamage to the LED.

Another problem with simply replacing an incandescent lamp of anexisting flashlight with an LED module is that it fails to address thethermal consequences associated with LEDs. Although LEDs produce lightmore efficiently than their incandescent counterparts, LEDs generatesignificantly more heat. Therefore, effective dissipation of heat isneeded to maintain the LED temperature within its design limits. Oneeffective way of dissipating heat generated by a light source in aflashlight is disclosed in a co-pending application Ser. No. 10/922,714entitled Improved LED Flashlight, filed Aug. 20, 2004, which is herebyincorporated by reference.

However, in the case of an LED module that is designed for retrofit, theexisting flashlight into which the LED module is used may not be able tosufficiently dissipate the increased heat that is produced by the LED.Most LEDs have projected life and lumen capacity that is conditioned onmaintaining a prescribed LED operating temperature. If this temperatureis not maintained, the life and/or the strength of the light generatedby the LED diminishes. Accordingly, if the existing flashlight intowhich the LED module is retrofitted is insufficient in this regard, theLED module itself must self-control the amount of heat that the LEDgenerates to ensure that the LED or the electronics that may control theLED are not damaged.

Existing LED modules have attempted to address the thermal dissipationproblem by limiting the current delivered to the LED to a continuousvalue at a safe level much below its potential light emitting capacity.However, such an approach makes inefficient use of the LED's lightingcapacity and the LED's full lighting potential is never achieved.

SUMMARY OF THE INVENTION

The present invention involves a lighting module that is energyregulating and thermally self-stabilizing, and that is able to beretrofitted into an existing flashlight.

In one embodiment, the lighting module includes an LED, an amplifyingcircuit and a microchip. The amplifying circuit has a thermistorarranged to sense heat from the LED. The microchip is coupled to theamplifying circuit and a switching device to regulate the energy that isdelivered to the LED. The switching device may be part of a boostingcircuit, a bucking circuit or an inverting circuit.

In a second embodiment, the lighting module includes a conductivehousing, an LED, and a circuit board. The circuit board includes amodule circuit that is electrically coupled to the LED. The circuit isat least partially contained within the cavity of the housing and alsohas a thermistor to sense heat from the LED. The thermistor may becoupled to an amplifying circuit. The gain of the amplifying circuit mayadjust according to the temperature senses by the thermistor. The outputof the amplifying circuit may also be the input to a microchip.

In another embodiment, the module can have a module circuit that isconfigured to regulate energy that is delivered to the LED based on thesensed temperature of the LED. In yet another embodiment, the LED modulecan have a module circuit that includes an energy regulating circuit anda thermal sensitive amplifying circuit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a circuit diagram of one embodiment of a main circuit of anelectronic device.

FIG. 1B is a sectional view of a flashlight embodying the main circuitof FIG. 1A.

FIG. 2 is an enlarged sectional view of the forward section of theflashlight of FIG. 1B.

FIG. 3 is a circuit diagram of one embodiment of a module circuit.

FIG. 4A is a sectional view of an LED module implementing the modulecircuit of FIG. 3.

FIG. 4B is an exploded view of an LED module implementing the modulecircuit of FIG. 3.

FIG. 4C is a perspective view of an LED module implementing the modulecircuit of FIG. 3.

FIG. 5 is a circuit diagram of a second embodiment of a module circuit.

FIG. 6 is a circuit diagram of a third embodiment of a module circuit.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Turning now to the drawings, as shown in FIG. 1A, a schematic depictionof one embodiment of a main circuit 70 of an electronic device includesa power source 2, a main switch 4, and an LED module 40. Energy from thepower source 2 preferably drives the LED module 40, and the main switch4 controls the energy that is delivered to the LED module 40. In oneembodiment of the present invention, the main switch 4 simply allows ordisrupts the available energy from the power source 2 to reach the LEDmodule 40.

Referring to FIG. 1B, the main circuit 70 is shown in one embodiment ofa flashlight 10. The flashlight 10 includes a barrel 12, a tailcapassembly 20, a head assembly 30, the LED module 40, and a main switchassembly 50. In the embodiment illustrated, the barrel 12 encases twobatteries 14, 15. The head assembly 30 and the LED module 40 arepreferably disposed about the forward end of the barrel 12; the tailcapassembly 20 is preferably disposed to enclose the aft end of the barrel12; and the main switch assembly 50 is preferably interposed between theLED module 40 and batteries 14, 15.

In the illustrated embodiment, the batteries 14, 15 serve as the powersource 2 of the main circuit 70. In a preferred embodiment, thebatteries 14, 15 are alkaline type dry cell batteries. However, othersuitable portable sources of energy may be used including rechargeabletype batteries, such as Lithium-Ion, Nickel Metal Hydride orNickel-Cadmium cells.

The barrel 12 preferably has a length suitable to contain a desirednumber of batteries. In the illustrated embodiment, the barrel 12 has alength suitable for containing two batteries 14, 15. However, barrelshaving various lengths are contemplated herein to receive one or morebatteries.

In the illustrated embodiment, the main switch assembly 50 serves as themain switch 4 of the main circuit 70. Referring to FIG. 2, energy fromthe batteries 14, to the main switch assembly 50 preferably flowsthrough a contact button 16 that is interposed between the forwardmostbattery 14 and the main switch assembly 50.

The main switch assembly 50 preferably includes a user interface 68, aplunger 72, a snap dome 73, a main switch circuit board 74, a mainswitch battery contact 75, a main switch module contact 76, and a switchhousing 77. In the illustrated embodiment, the center electrode of theforwardmost battery 14 is electrically coupled to the main switchbattery contact 75 through the contact button 16; the main switchbattery contact 75 is electrically coupled to the main switch circuitboard 74; and the main switch circuit board 74 is electrically coupledto the main switch module contact 76.

The main switch assembly 50 is preferably a momentary switch. When theuser interface 68 is depressed, the plunger 72 pushes the snap dome 73into contact with a select portion of the main switch circuit board 74.This momentary contact is received as a signal to the switch circuitboard 74 which in turn passes or disrupts the energy flow from thebatteries 14,15 to the main switch module contact 76. In this way, themain switch assembly 50 can turn the flashlight 10 on or off. The mainswitch circuit board 74 may additionally include circuitry suitable forproviding functions to the flashlight 10, such as for example, flashing,dimming or strobing by affecting the current that is delivered to alight source or, in the illustrated embodiment, the LED module 40. Otherfunctions may include an electronic game, a global positioningtransponder, a digital compass, or other commercially desirablefunctions.

Still referring to the illustrated embodiment of FIG. 2, the main switchbattery contact 75 and module contact 76 are configured to includecurved springs or biasing elements that bear against the contact button16 and spring 17, respectively. By arranging the curved spring portionof the main switch battery contact 75 and module contact 76 against theswitch housing 77 such that the spring forces generated by the contacts75, 76 are transferred to the switch housing 77, the main switch circuitboard 74 is advantageously protected from, for example, batteries 14, 15shifting and pressing on the main switch assembly 50. In this way, aneffective electrical connection can be maintained by the biasingelements while protecting sensitive components, such as the main switchcircuit board 74.

Although the main switch assembly 50 as described above provides aconfiguration for turning the flashlight 10 on and off, other suitableswitches are available for serving this function, such as a simplemechanical switch. However, the main switch assembly 50 as disclosedherein advantageously provides a flexible configuration for adding,revising or deleting functions from the flashlight 10. Also, the mainswitch assembly 50 as described avoids high oxidation problem betweencontacts often experienced with mechanical switches.

Still referring to FIG. 2, the current flowing from the main switchassembly 50 to the LED module 40 is preferably achieved through thespring 17 and a receptacle 18, (which is disposed about the forward endof the spring 17,) that are electrically connected to the main switchmodule contact 76 on one end and to the LED module 40 on the other end.The spring 17 urges the receptacle 18 toward the positive contact of theLED module 40. In the illustrated embodiment, the current flows into theLED module 40 at its positive contact 28, and flows out of the LEDmodule 40 at its outer housing 24. The electrical energy then preferablypasses through conductive means to the barrel 12, through the tailcapassembly 20; and returns to the negative end of the aftmost battery 15.In this way, the main circuit 70 of the flashlight 10 is completed.

The barrel 12 is preferably made from a conductive material, preferablyaluminum, so that it may serve as part of the current path of the maincircuit 70 between the LED module 40 and the power source 2, i.e.,batteries 14, 15. However, the barrel 12 may alternatively be made ofnon-conductive material, such as plastic or rubber, and may include acurrent path by having a conductive sleeve within a non-conductivebarrel to serve as part of the current path. Such a sleeve is describedin U.S. Pat. Nos. 4,656,565 and 4,851,974 to Anthony Maglica, which ishereby incorporated by reference. In an alternate embodiment, aconductive strip within the barrel can serve as part of the currentpath. Such a strip is shown in U.S. Pat. No. 6,585,391.

Referring to FIG. 1B, the tailcap assembly 20 preferably includes a capspring 6 and a cap 8. The tail cap assembly 20 may be part of thecurrent path between the LED module 40 and the power source 2, and mayreceive the current passing through the barrel 12. In one embodiment,the electrical path from the barrel 12 may be to the cap 8; to the capspring 6, and then to the negative contact of the aftmost battery 15.Alternatively, the electrical path may bypass the cap 8 and flowdirectly from the barrel 12 to the battery 15 through the cap spring 6.Another embodiment may provide an electrical path that bypasses thetailcap assembly 20 altogether and electrically connect the barrel 12 tothe battery. A tailcap assembly 20 having a cap spring 6 provides aneffective configuration for maintaining a spring assisted electricalconnection between the components contained in the flashlight 10.

As shown in FIG. 1B and FIG. 2, the head assembly 30 includes a head 31,a reflector 33, a lens 35 and a cap 39. The reflector 33 and lens 35 areinterposed between the head 31 and the cap 39 as illustrated in FIG. 2.The reflector 33 preferably includes a reflective parabolic surface toreflect the light emanating from the LED module 40. The head assembly 30may be secured to the barrel 12 by thread engagement.

As already mentioned, and schematically depicted in FIG. 1A, the currentfrom the power source 2 flows into the LED module 40 at its positivecontact 28 and flows out of the LED module 40 from its outer housing 24.Referring to FIG. 3, a schematic depiction of one embodiment of the LEDmodule 40 according to the present invention generally includes an LEDlamp 22 and a module circuit 38.

Referring to FIG. 3, 4A, 4B and 4C, the LED lamp 22 is preferablycommercially available and includes an LED and LED leads 82, 83 to whichthe module circuit 38 connects. Typically, LED's are rated according topermissible operating conditions. For example, an LED may be limited toa maximum forward current rating of 1000 mA, and a maximum LED junctiontemperature of 135° C.

An objective of the present invention is to have the LED lamp 22 produceas much light as possible, for as long as possible, without damaging theLED lamp 22 or the electronics that make up the LED module 40. Thisobjective is achieved by regulating the current that flows to the LEDlamp 22 and monitoring the heat that is generated from the LED lamp 22.In a preferred embodiment, a temperature sensing device is disposedwithin the LED module 40 to monitor the conditions surrounding the LED.When an undesirable increase in temperature is sensed, the currentdelivered to the LED lamp 22 may be decreased to protect the LED and theelectronics from heat damage. When an undesirable decrease intemperature is sensed, the current delivered to the LED lamp 22 may beincreased to cause the LED lamp 22 to produce more light.

Referring to FIG. 3, a first embodiment of the module circuit 38preferably includes a controlled voltage boosting circuit 44, a thermalsensitive amplifying circuit 52, and a sense resistor 48. The voltageboosting circuit 44 is controlled because it includes feedback to adjustits output. The boosting circuit 44 is useful in situations where thepower source 2 driving the LED module 40 has a maximum potential that isbelow what is needed to deliver the desired forward current. Forexample, in a case where flashlight 10 includes two alkaline type drycell batteries arranged in series, it is generally known that the twobatteries will have an operating range of 1.8 Volts to 3.0 Volts. But3.5 Volts may be needed to deliver a forward current that is closer tothe LED's maximum forward current rating. In such a situation, theboosting circuit 44 steps up the available voltage to approximately 3.5Volts so that the desired forward current may be delivered to the LEDlamp 22. The boosting circuit 44 also serves to maintain the desiredforward current as the voltage level of the batteries diminish overtime.

In a preferred embodiment, the boosting circuit 44 is a switchingregulator. Referring to FIG. 3, the boosting circuit 44 includes amicrochip 46, a switching MOSFET 54, an inductor 58, a capacitor 59, anda diode 61. The microchip 46 controls the switching duty cycle of theswitching MOSFET 54. As illustrated, the switching MOSFET 54, inductor58, the capacitor 59, and the diode 61 are arranged in a manner commonlyknown to those skilled in the art to form a boost converter. Themicrochip 46 receives feedback by way of the thermal sensitiveamplifying circuit 52. When the feedback is outside a specifiedregulation range, the microchip adjusts the MOSFET's duty cycle untilthe regulation range is met.

The boosting circuit 44 described herein may be composed of othersuitable circuitry or devices that step up the input voltage. Forexample, instead of having the inductor 58 as the energy-storage elementof the boosting circuit 44, other suitable energy storage elements, suchas a capacitor or a transformer, may also be used. Also, other suitableswitching devices, such as a transistor, may be used instead of theswitching MOSFET 54.

Still referring to FIG. 3, an electrical path connects the output of theboosting circuit 44 to the first LED reception contact 36; and the firstLED reception contact 36 is coupled to the first LED lead 82. Thecurrent flows out of the LED lamp 22 through the second LED lead 83,which is coupled to the second LED reception contact 37. The main powerpath is through the sense resistor 48 and to ground contact 34. Thesense resistor 48 is used to measure the current that is passing throughthe LED lamp 22, and the voltage measured across the sense resistor 48serves as feedback to the microchip 46. Preferably, the sense resistor48 is very small to minimize power waste. In a preferred embodiment, thesense resistor 48 has a value of 0.10 ohms.

Because the sense resistor 48 is very small, the voltage that formsacross the sense resistor 48 is also very small. Therefore, before thesense resistor voltage is fed back to the microchip 46, it is amplifiedby the amplifier circuit 52.

The thermal stabilizing aspect of the present invention is implementedin the thermal sensitive amplifying circuit 52. Still referring to FIG.3, the amplifying circuit 52 includes an operational amplifier 62, afirst resistor 64, a second resistor 66, and a thermistor 56. Thethermistor 56 is arranged in parallel with the second resistor 66. Asconfigured, it is understood by those skilled in the art that the firstresistor 64, the second resistor 66 and the thermistor 56, incombination, define the gain of the amplifying circuit 52. Thethermistor 56 is a temperature responsive resistor that changes itsresistance according to the sensed temperature. Therefore, as the sensedLED lamp 22 temperature varies, the gain of the amplifying circuit 52varies.

In a preferred embodiment, the thermistor 56 has a negativeresistance/temperature coefficient. Accordingly, when the temperature ofthe LED module 40 increases, the thermistor resistance decreases, andthe gain of the amplifier circuit 52 increases. With the microchipfeedback above the regulation range, the microchip 46 decreases the dutycycle of the switching MOSFET 54 and reduces the current that isdelivered to the LED lamp 22. In this way, the temperature effects ofthe LED lamp 22 can be monitored and prevented from damaging the LED orthe controlling electronics. In a preferred embodiment, the microchip 46is configured to regulate the current delivered to the LED lamp 22 toapproximately between 875 mA and 930 mA at a thermistor sensedtemperature of between 20° C. to 30° C.; between 880 mA and 910 mA atbetween 23° C. to 27° C.; and substantially 900 mA at 25° C.

At a higher temperature, the microchip 46 is preferably configured toregulate the current delivered to the LED lamp 22 to approximatelybetween 330 mA and 450 mA at a thermistor sensed temperature of between80° C. to 100° C.; 330 mA to 370 mA at 90° C. to 100° C.; andsubstantially 330 mA at 100° C.

Although these temperature/current ranges have been found to effectivelypresent an LED from heat damage, the current invention should not beviewed to be limited to any specific temperature/current range. Rather,the instant invention is directed to an LED module that operates the LEDat is potential, and that is thermally self-stabilizing.

Although a thermistor having a negative resistance/temperaturecoefficient is disclosed herein, a thermistor having a positiveresistance/temperature coefficient may also be used. Moreover, othersuitable temperature sensing devices, such as a voltage outputtemperature sensor, may be used instead of a thermistor.

Further, a suitable microchip 46 for this application may be aprocessor, a microprocessor, a controller, an integrated circuit, anASIC, or other devices known to those skilled in the art.

In this way, the LED module 40 allows the initial operation of theflashlight to be at a high power output, and to deliver more light,while protecting the electronics from heat damage. Without the thermalstabilizing capability as described and illustrated above, driving theLED lamp 22 at 750 mA may result in heat damage to the LED. Operatingthe LED lamp 22 at lower current will result in less light.

Having now described the schematic depiction of one embodiment of theLED module 40, a preferred physical implementation of the LED module 40is illustrated in FIGS. 4A, 4B, and 4C. The LED module 40 includes theLED lamp 22, the outer housing 24, a circuit assembly 60, and a holder26. The circuit assembly 60 is preferably held in the holder 26; theholder 26 is preferably arranged within the outer housing 24; and theLED lamp 22 is preferably disposed on the forward end of the holder 26.

Preferably, the outer housing 24 is made from a conductive material. Inthe illustrated embodiment, the outer housing 24 is generally areceptacle including a first end 88, a second end 92 and a cavity 94.The cavity 94 may include features, such as slots, to receive and alignholder 26 therein.

In a preferred embodiment, the circuit assembly 60 includes a circuitboard 32, the positive contact 28, a negative contact 34, and first andsecond LED reception contacts 36, 37. Preferably, the components of themodule circuit 38, including the thermistor 56, are mounted to thecircuit board 32 with necessary traces printed thereon. The circuitassembly 60 is configured to be held in the holder 26. Referring to FIG.4A, the positive contact 28 of the circuit assembly 60 preferablyextends through an opening 78 on the aft end of the holder 26. Thepositive contact 28 is preferably folded over to bear against the aftend of the holder 26 for support. The negative contact 34 of the circuitassembly 60 is preferably disposed about the forward end of the circuitboard 32 and arranged to electrically connect to the outer housing 24.Arranged this way, the circuit components mounted on the circuit board32 is advantageously protected from mechanical forces, such as from thespring 17 and receptacle 18.

Referring to FIGS. 4B and 4C, LED leads 82, 83 extend through openingsabout the first end 88 of the outer housing 24, and electrically coupleto the first and second LED reception contacts 36, 37 of the circuitassembly 60. Preferably, the electrical connection between the LEDreception contacts 36, 37 and the LED lead 82, 83 are mechanical, orparticularly, by friction, to ease manufacturing and production costs.However, any suitable electrical connection methods, such as soldering,can be used.

Arranged as described, the components of the module circuit 38 aremounted to the circuit board 32 and contained in the LED module 40. Thephysical arrangement of the LED module 40 as just described is onesuitable way to implement the module circuit 38 and operate the LED lampat its lighting potential while protecting the electronics from heatdamage by monitoring the heat generated from the LED and decreasing thecurrent flowing thereto if necessary. The external dimensions of the LEDmodule 40, and particularly the outer housing 24, is preferablyconsistent with PR type light bulbs. Having such an external dimensionfacilitates retrofitting the LED module 40 as described herein intoexisting flashlights that receive incandescent PR type light bulbs.However, the present invention as described herein is not limited by theexternal dimension or features as illustrated. The benefits andadvantages of an LED module that operates the LED at its potential, thatis thermally self-stabilizing, and that is able to be retrofitted intoan existing flashlight may be achieved through numerous externalconfigurations.

The flow of energy through the flashlight 10, and particularly throughthe LED module 40, will now be described. Electrical current from thebatteries 14, 15 flows through the main switch assembly 50 and into theLED module at the positive contact 28. The positive contact 28 iselectrically connected to the module circuit 38 mounted on the circuitboard 32 and the main power flows to the boosting circuit 44. The outputof the boosting circuit 44 flows to the first LED reception contact 36,then to the LED lead 82 and through the LED. The electrical currentflows out of the LED lamp 22 through the second LED lead 83, which iscoupled to the second LED reception contact 37. The main power passesthrough the sense resistor 48 and to the negative contact 34 of thecircuit assembly 60, while the sense resistor 48 voltage is directed tothe thermal sensitive amplifying circuit 52.

The main power then passes through the sense resistor and to thenegative contact 34 which is coupled to the outer housing 24. The outerhousing 24 is coupled to the barrel 12, the tailcap assembly 20, andfinally to the negative end of the aftmost battery 15 to complete themain circuit.

The sense resistor 48 voltage is amplified by the thermal sensitiveamplifying circuit 52 according to a gain that is a function of the LEDlamp 22 temperature. The output of the thermal sensitive amplifyingcircuit 52 is feedback to the microchip 46 which regulates the currentthat is delivered to the LED lamp 22 by adjusting the duty cycle of theswitching MOSFET 54.

In a second embodiment of an LED module 40 a, the power source 2 coupledto the LED module 40 a may have a potential that is above what is neededto deliver the desired forward current. For example, in the instancewhere a flashlight includes four batteries arranged in series, it wouldhave an operating range of 3.6 Volts to 6.0 Volts. In such an instance,the module circuit 38 a preferably includes a controlled voltage buckingcircuit 84 in place of a boosting circuit 44. Referring to FIG. 5, aschematic depiction of this second embodiment of the LED module 40 agenerally includes an LED lamp 22 and a module circuit 38 a. The modulecircuit 38 a includes a controlled voltage bucking circuit 84, the senseresistor 48, and the thermal sensitive amplifying circuit 52. Thevoltage bucking circuit 84 is controlled because it includes feedback toadjust its output. The bucking circuit 84 output drives the LED lamp 22,and receives the sense resistor 48 feedback through the thermalsensitive amplifying circuit 52.

Referring to FIG. 5, the bucking circuit 84 is preferably a buckregulator or a bucking circuit and includes a microchip 46 a, aswitching MOSFET 54 a, an inductor 58 a, a capacitor 59 a, and a diode61 a. These components are arranged in a manner commonly known to thoseskilled in the art to form a bucking circuit.

In a third embodiment of an LED module 40 b, the power source 2 coupledto the LED module 40 b may have a potential above what is needed todeliver the desired forward current during a first period of time, and apotential below what is needed during a second period of time. Forexample, if a flashlight is configured with three batteries arranged inseries, its operating range would be 2.7 Volts to 4.5 Volts. In such aninstance, the module circuit 38 b preferably includes an controlledvoltage inverting circuit 86 instead of the boosting circuit 44 or thebucking circuit 84. Referring to FIG. 6, a schematic depiction of athird embodiment of the LED module 40 b generally includes an LED lamp22 and a module circuit 38 b. The module circuit 38 b includes acontrolled voltage inverting circuit 86, the sense resistor 48, and thethermal sensitive amplifying circuit 52. The inverting circuit 86 iscontrolled because it includes feedback to adjust its output. Theinverting circuit 86 output drives the LED lamp 22, and receives thesense resistor 48 feedback through the thermal sensitive amplifyingcircuit 52.

Referring to FIG. 6, the inverting circuit 86 is preferably an invertingregulator or inverting circuit and includes a microchip 46 b, aswitching MOSFET 54 b, an inductor 58 b, a capacitor 59 b, and a diode61 b. These components are arranged in a manner commonly known to thoseskilled in the art to form a inverting circuit.

While various embodiments of an improved LED module and its respectivecomponents have been presented in the foregoing disclosure, numerousmodifications, alterations, alternate embodiments, and alternatematerials may be contemplated by those skilled in the art and may beutilized in accomplishing the various aspects of the present invention.Thus, it is to be clearly understood that this description is made onlyby way of example and not as a limitation on the scope of the inventionas claimed below.

What is claimed is:
 1. A lighting module for flashlights, said lightingmodule comprising: a light emitting diode; an amplifying circuitincluding a thermistor, said thermistor arranged to sense heat from saidlight emitting diode; and a microchip having an input and an output,said amplifying circuit coupled to said input, said output coupled to aswitching device that regulates energy delivered to the light emittingdiode.
 2. A lighting module of claim 1, wherein said switching device ispart of a boosting circuit.
 3. A lighting module of claim 1, whereinsaid switching device is part of a bucking circuit.
 4. A lighting moduleof claim 1, wherein said switching device is part of an invertingcircuit.
 5. A lighting module of claim 1, wherein said switching deviceis a MOSFET.
 6. A lighting module of claim 1, wherein said microchip isconfigured to operate the switching device such that 875 mA to 930 mA isdelivered to the light emitting diode when said thermistor sensesbetween 20° C. to 30° C.
 7. A lighting module of claim 1, wherein saidmicrochip is configured to operate the switching device such that 880 mAto 910 mA is delivered to the light emitting diode when said thermistorsenses between 23° C. to 27° C.
 8. A lighting module of claim 1, whereinsaid microchip is configured to operate the switching device such thatsubstantially 900 mA is delivered to the light emitting diode when saidthermistor senses 25° C.
 9. A lighting module of claim 1, wherein saidmicrochip is configured to regulate the energy that is delivered to saidlight emitting diode by adjusting the switching duty cycle of saidswitching device.
 10. A lighting module of claim 1, wherein saidmicrochip is configured to operate the switching device such that 330 mAto 450 mA is delivered to the light emitting diode when said thermistorsenses between 80° C. to 100° C.
 11. A lighting module of claim 1,wherein said microchip is configured to operate the switching devicesuch that 330 mA to 370 mA is delivered to the light emitting diode whensaid thermistor senses between 90° C. to 100° C.
 12. A lighting moduleof claim 1, wherein said microchip is configured to operate theswitching device such that substantially 330 mA is delivered to thelight emitting diode when said thermistor senses 100° C.
 14. A lightingmodule of claim 1, wherein said microchip is a microprocessor.
 15. Alighting module of claim 1, wherein said microchip is an integratedcircuit.
 16. A lighting module of claim 1, wherein said microchip isenergized by a power source, wherein the energy of said power sourcedepletes over time.